Enable Docker container to generate its own VAPID credentials

- Move push subscription handling to Notifier class
- Allow duplicate options in config
- Only save subscription in frontend if sub call was successful

Dockerfile

@@ -1,7 +1,9 @@
 FROM alpine:latest
 
 RUN apk add --update --no-cache \
-	bash python3 py3-pip nginx uwsgi uwsgi-python3 certbot certbot-nginx
+	bash python3 py3-pip nginx uwsgi uwsgi-python3 certbot certbot-nginx npm jq
+
+RUN npm install -g web-push
 
 
 

config.ini

@@ -30,3 +30,5 @@ json_indent = 4
 # sender info: usually mailto link to responsible party to contact about issues
 push_private_key = abcdefghijklm_NOPQRSTUVWXYZ-0123456789
 push_sender_info = mailto:it@fasttube.de
+# when to notify users, in hours after arrival
+notify_after_hrs = 10

ftracker/config.py

@@ -19,7 +19,7 @@ class Config:
 		configfile = findConfigFile()
 
 		if configfile:
-			self.config = ConfigParser()
+			self.config = ConfigParser(strict=False)
 			self.config.read(configfile)
 		else:
 			raise Exception("No config file found")
@@ -30,3 +30,6 @@ class Config:
 
 	def __getitem__(self, key):
 		return self.config['global'].get(key)
+
+	def __repr__(self):
+		return repr(self.config.items('global'))

ftracker/core.py

@@ -22,14 +22,19 @@ from flask import Flask, request, redirect
 app = Flask(__name__, static_folder='../web')
 
 
-from pywebpush import webpush, WebPushException
-pushsubs = db.table('pushsubs')
-
-
 if config['delete_after_days']:
 	from .deleter import Deleter
 	deleter = Deleter(db, int(config['delete_after_days']))
 
+
+if config['notify_after_hrs']:
+	from .notifier import Notifier
+	notifier = Notifier(db, int(config['notify_after_hrs']), {
+		'private_key': config['push_private_key'],
+		'claims': {'sub': config['push_sender_info']}
+	})
+
+
 def shutdown():
 	print('\rReceived stop signal, stopping threads...')
 	deleter.stop()
@@ -37,6 +42,7 @@ def shutdown():
 
 atexit.register(shutdown)
 
+
 @app.route('/guidelines')
 def get_guidelines():
 	dest = config['guideline_url'] or None
@@ -174,44 +180,32 @@ def post_pushsub():
 	except ValueError as e:
 		return 'Error: JSON decode error:\n' + str(e), 400
 
-	name = slugify(data['name'])
-	data['name'] = name
-	print(json.dumps(data, indent=SPACES))
-
-	Entry = Query()
-	pushsubs.upsert(data, Entry.name == name)
+	notifier.subscribe_user(data)
 
 	return 'OK', 201
 
 @app.route('/testpush/<name>')
 def testpush(name):
 
+	if not 'Authorization' in request.headers:
+		return 'Error: No Authorization', 401, {'WWW-Authenticate': 'Basic'}
+
+	if request.authorization.username != config['admin_user']:
+		return "Wrong username", 403
+
+	if request.authorization.password != config['admin_pass']:
+		return "Wrong password", 403
+
 	Entry = Query()
-	ps = pushsubs.search(Entry.name == name)[0]
+	arrivals = db.search((Entry.name == name) & (Entry.departure == None))
 
-	arr = db.search((Entry.name == name) & (Entry.departure == None))
-	arr = arr if len(arr) else None
+	if len(arrivals) == 0:
+		print("User is not logged in :(")
+		return "Error: User is not logged in :(", 409
 
-	print(ps)
+	error = notifier.notify_user(arrivals[0])
 
-	subscription = ps['sub']
-	notification = {
-		'title': "Forgot to sign out?",
-		'body': "You didn't sign out of ftracker yet",
-		'arr': arr
-	}
+	if error:
+		return 'Error: ' + error, 404
 
-	try:
-		webpush(
-			subscription,
-			json.dumps(notification, indent=SPACES),
-			vapid_private_key = config['push_private_key'],
-			vapid_claims = {
-				'sub': config['push_sender_info']
-			},
-			verbose=True
-		)
-		return 'OK', 201
-	except WebPushException as exc:
-		print(exc)
-		return 'Error', 500
+	return 'OK', 201

ftracker/notifier.py

@@ -0,0 +1,97 @@
+import json
+from slugify import slugify
+from threading import Thread, Event
+from datetime import datetime, timedelta
+
+from tinydb import Query
+
+from pywebpush import webpush, WebPushException
+
+ONE_HOUR_IN_S = 60 * 60
+
+class Notifier(Thread):
+
+	def subscribe_user(self, data):
+
+		pushsubs = self.db.table('pushsubs')
+
+		name = slugify(data['name'])
+		data['name'] = name
+
+		Entry = Query()
+		pushsubs.upsert(data, Entry.name == name)
+
+	def notify_user(self, arrival):
+
+		pushsubs = self.db.table('pushsubs')
+
+		Entry = Query()
+		ps = pushsubs.search(Entry.name == arrival['name'])
+		if len(ps) == 0:
+			print("User is not subscribed to notifications :(")
+			return "User is not subscribed to notifications :("
+
+		ps = ps[0]
+
+		print("Sending notification", arrival, ps)
+
+		subscription = ps['sub']
+		notification = {
+			'title': "Forgot to sign out?",
+			'body': "You didn't sign out of ftracker yet",
+			'arr': arrival
+		}
+
+		try:
+			webpush(
+				subscription,
+				json.dumps(notification),
+				vapid_private_key = self.vapid_creds['private_key'],
+				vapid_claims = self.vapid_creds['claims']
+			)
+			print("Notification sent")
+			return None
+		except WebPushException as exc:
+			print("Notification failed", exc)
+			return repr(exc)
+
+
+	def notify_logged_in_users(self):
+
+		print("Notifying users that aren't signed out yet...")
+
+		td = timedelta(hours=self.hours)
+
+		threshold = datetime.utcnow() - td
+
+		iso = threshold.isoformat() + 'Z'
+
+		Entry = Query()
+		arrivals = self.db.search(
+			(Entry.arrival < iso) & (Entry.departure == None)
+		)
+
+		for arrival in arrivals:
+			self.notify_user(arrival)
+
+		print("Notified everything until UTC", iso)
+
+	def __init__(self, db, hours, vapid_creds):
+
+		self.db = db
+		self.hours = hours
+		self.vapid_creds = vapid_creds
+
+		self.notify_logged_in_users()
+
+		Thread.__init__(self, daemon=True)
+		self.stopped = Event()
+		self.start()
+
+	def run(self):
+
+		while not self.stopped.wait(ONE_HOUR_IN_S):
+			self.notify_logged_in_users()
+
+	def stop(self):
+		self.stopped.set()

res/config.deploy.ini

@@ -4,6 +4,9 @@
 # Remove or leave empty for temporary (/tmp/ftracker-db.json) storage
 db_file = /var/ftracker/db.json
 
+# Delete all information after X days (e.g. for GDPR compliance)
+delete_after_days = 28
+
 # List of people to be allowed, in .csv format (comma, no delimiters)
 # Col1: First Name(s), Col2: Last Name(s), Col3 (optional): EMail
 # Remove or leave empty for no check
@@ -21,3 +24,11 @@ guideline_url = https://youtu.be/oHg5SJYRHA0
 
 # JSON indentation for debugging
 json_indent = 4
+
+# VAPID credentials for push notifications
+# private key: base64url encoded private part of an EC-Prime256v1 keypair. See INSTALL.md
+# sender info: usually mailto link to responsible party to contact about issues
+push_private_key = abcdefghijklm_NOPQRSTUVWXYZ-0123456789
+push_sender_info = mailto:admin@example.com
+# when to notify users, in hours after arrival
+notify_after_hrs = 10

res/docker-entrypoint.sh

@@ -1,5 +1,25 @@
 #!/bin/bash
 
+echo " >>> Checking / Creating & patching VAPID creds <<< "
+
+VAPID_CREDS_FILE=/etc/ftracker/vapid-creds.json
+if [[ ! -f $VAPID_CREDS_FILE ]]
+then
+
+	echo "Generating keypair ..."
+
+	web-push generate-vapid-keys --json > $VAPID_CREDS_FILE
+
+	echo "Patching public key into frontend ..."
+	PUB_KEY=`cat $VAPID_CREDS_FILE | jq -r .publicKey`
+	sed -i "s/pushServerPublicKey = '[a-zA-Z0-9_\-]*'/pushServerPublicKey = '${PUB_KEY}'/" /var/www/html/ftracker/main.js
+
+	echo "Patching private key into backend config ..."
+	PRIV_KEY=`cat $VAPID_CREDS_FILE | jq -r .privateKey`
+	echo "push_private_key = ${PRIV_KEY}" >> /etc/ftracker/config.ini
+
+fi
+
 echo " >>> Starting nginx <<< "
 
 mkdir /run/nginx # needed because of bug in package

web/main.js

@@ -250,7 +250,6 @@ function initPush(name) {
 			applicationServerKey: pushServerPublicKey
 		}).then(function(subscription) {
 			console.log("User is subscribed:", subscription);
-			localStorage.setItem('pushsub', subscription);
 
 			fetch('/pushsubscribe', {
 				method: "POST",
@@ -259,6 +258,9 @@ function initPush(name) {
 					name: name,
 					sub: subscription
 				})
+			}).then(function(res) {
+				if (res.ok)
+					localStorage.setItem('pushsub', subscription);
 			});
 		});
 	});